Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 120(10): e2214076120, 2023 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-36848567

RESUMO

Lentinula is a broadly distributed group of fungi that contains the cultivated shiitake mushroom, L. edodes. We sequenced 24 genomes representing eight described species and several unnamed lineages of Lentinula from 15 countries on four continents. Lentinula comprises four major clades that arose in the Oligocene, three in the Americas and one in Asia-Australasia. To expand sampling of shiitake mushrooms, we assembled 60 genomes of L. edodes from China that were previously published as raw Illumina reads and added them to our dataset. Lentinula edodes sensu lato (s. lat.) contains three lineages that may warrant recognition as species, one including a single isolate from Nepal that is the sister group to the rest of L. edodes s. lat., a second with 20 cultivars and 12 wild isolates from China, Japan, Korea, and the Russian Far East, and a third with 28 wild isolates from China, Thailand, and Vietnam. Two additional lineages in China have arisen by hybridization among the second and third groups. Genes encoding cysteine sulfoxide lyase (lecsl) and γ-glutamyl transpeptidase (leggt), which are implicated in biosynthesis of the organosulfur flavor compound lenthionine, have diversified in Lentinula. Paralogs of both genes that are unique to Lentinula (lecsl 3 and leggt 5b) are coordinately up-regulated in fruiting bodies of L. edodes. The pangenome of L. edodes s. lat. contains 20,308 groups of orthologous genes, but only 6,438 orthogroups (32%) are shared among all strains, whereas 3,444 orthogroups (17%) are found only in wild populations, which should be targeted for conservation.


Assuntos
Lentinula , Filogenia , Ásia Oriental , Tailândia
2.
Antioxidants (Basel) ; 11(5)2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35624779

RESUMO

Vegetable oils are valuable renewable resources for the production of bio-based chemicals and intermediates, including reactive epoxides of industrial interest. Enzymes are an environmentally friendly alternative to chemical catalysis in oxygenation reactions, epoxidation included, with the added advantage of their potential selectivity. The unspecific peroxygenase of Collariella virescens is only available as a recombinant enzyme (rCviUPO), which is produced in Escherichia coli for protein engineering and analytical-scale optimization of plant lipid oxygenation. Engineering the active site of rCviUPO (by substituting one, two, or up to six residues of its access channel by alanines) improved the epoxidation of individual 18-C unsaturated fatty acids and hydrolyzed sunflower oil. The double mutation at the heme channel (F88A/T158A) enhanced epoxidation of polyunsaturated linoleic and α−linolenic acids, with the desired diepoxides representing > 80% of the products (after 99% substrate conversion). More interestingly, process optimization increased (by 100-fold) the hydrolyzate concentration, with up to 85% epoxidation yield, after 1 h of reaction time with the above double variant. Under these conditions, oleic acid monoepoxide and linoleic acid diepoxide are the main products from the sunflower oil hydrolyzate.

3.
Curr Alzheimer Res ; 15(2): 149-156, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28847285

RESUMO

BACKGROUND: Sensorimotor integration mechanisms can be affected by many factors, among which are those involving neuromuscular disorders. Parkinson's disease (PD) is characterized by well-known motor symptoms, among which lately have been included motor speech deficits. Measurement of the acoustic startle reflex (ASR) and its modulations (prepulse inhibition and prepulse facilitation, PPI and PPF respectively) represent a simple and quantifiable tool to assess sensorimotor function. However, it remains unknown whether measures of the PPI and PPF are associated with motor speech deficits in PD. METHODS: A total of 88 subjects participated in this study, 52 diagnosed with PD and 36 control subjects. After obtaining written informed consent, participants were assessed with PPI at several interstimulus intervals, and PPF at 1000 ms using the SRH-Lab system (San Diego, CA). Percentage of change in the amplitude and latency of the ASR was analyzed between groups. Voice recordings were register of a specific text given to the subjects with a professional recorder and temporal patterns of speech were analyzed. RESULTS: Statistical analysis conducted in this study showed differences in PPI and PPF in subjects with PD compared to controls. In addition, discriminative parameters of voice abnormalities were observed in PD subjects related to control subjects showing a reduction in phonation time, vowel pulses, breaks, breakage and voice speech periods. CONCLUSIONS: PD presents a disruption in sensorimotor filter mechanisms and speech disorders, and there is a relationship between these alterations. The correlation between the PPI and PPF with an alteration of the voice in PD subjects contributes toward understanding mechanism underlying the neurophysiological alterations in both processes. Overall, easy and non-invasive tests such as PPI, PPF together with voice analysis may be useful to identify early stages of PD.


Assuntos
Doença de Parkinson/fisiopatologia , Filtro Sensorial , Distúrbios da Fala/fisiopatologia , Idoso , Feminino , Humanos , Masculino , Filtro Sensorial/fisiologia , Fala/fisiologia , Medida da Produção da Fala , Voz/fisiologia
4.
Mycologia ; 107(6): 1105-19, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26297778

RESUMO

The genomes of three representative Polyporales (Bjerkandera adusta, Phlebia brevispora and a member of the Ganoderma lucidum complex) recently were sequenced to expand our knowledge on the diversity and distribution of genes involved in degradation of plant polymers in this Basidiomycota order, which includes most wood-rotting fungi. Oxidases, including members of the glucose-methanol-choline (GMC) oxidoreductase superfamily, play a central role in the above degradative process because they generate extracellular H2O2 acting as the ultimate oxidizer in both white-rot and brown-rot decay. The survey was completed by analyzing the GMC genes in the available genomes of seven more species to cover the four Polyporales clades. First, an in silico search for sequences encoding members of the aryl-alcohol oxidase, glucose oxidase, methanol oxidase, pyranose oxidase, cellobiose dehydrogenase and pyranose dehydrogenase families was performed. The curated sequences were subjected to an analysis of their evolutionary relationships, followed by estimation of gene duplication/reduction history during fungal evolution. Second, the molecular structures of the near one hundred GMC oxidoreductases identified were modeled to gain insight into their structural variation and expected catalytic properties. In contrast to ligninolytic peroxidases, whose genes are present in all white-rot Polyporales genomes and absent from those of brown-rot species, the H2O2-generating oxidases are widely distributed in both fungal types. This indicates that the GMC oxidases provide H2O2 for both ligninolytic peroxidase activity (in white-rot decay) and Fenton attack on cellulose (in brown-rot decay), after the transition between both decay patterns in Polyporales occurred.


Assuntos
Colina/metabolismo , Proteínas Fúngicas/genética , Glucose/metabolismo , Peróxido de Hidrogênio/metabolismo , Metanol/metabolismo , Oxirredutases/genética , Polyporales/enzimologia , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Genoma Fúngico , Modelos Moleculares , Oxirredutases/química , Oxirredutases/metabolismo , Filogenia , Polyporales/classificação , Polyporales/genética , Polyporales/metabolismo
5.
PLoS One ; 8(9): e73585, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24066057

RESUMO

INTRODUCTION: This study aimed to assess the top-down control of sound processing in the auditory brainstem of rats. Short latency evoked responses were analyzed after unilateral or bilateral ablation of auditory cortex. This experimental paradigm was also used towards analyzing the long-term evolution of post-lesion plasticity in the auditory system and its ability to self-repair. METHOD: Auditory cortex lesions were performed in rats by stereotactically guided fine-needle aspiration of the cerebrocortical surface. Auditory Brainstem Responses (ABR) were recorded at post-surgery day (PSD) 1, 7, 15 and 30. Recordings were performed under closed-field conditions, using click trains at different sound intensity levels, followed by statistical analysis of threshold values and ABR amplitude and latency variables. Subsequently, brains were sectioned and immunostained for GAD and parvalbumin to assess the location and extent of lesions accurately. RESULTS: Alterations in ABR variables depended on the type of lesion and post-surgery time of ABR recordings. Accordingly, bilateral ablations caused a statistically significant increase in thresholds at PSD1 and 7 and a decrease in waves amplitudes at PSD1 that recover at PSD7. No effects on latency were noted at PSD1 and 7, whilst recordings at PSD15 and 30 showed statistically significant decreases in latency. Conversely, unilateral ablations had no effect on auditory thresholds or latencies, while wave amplitudes only decreased at PSD1 strictly in the ipsilateral ear. CONCLUSION: Post-lesion plasticity in the auditory system acts in two time periods: short-term period of decreased sound sensitivity (until PSD7), most likely resulting from axonal degeneration; and a long-term period (up to PSD7), with changes in latency responses and recovery of thresholds and amplitudes values. The cerebral cortex may have a net positive gain on the auditory pathway response to sound.


Assuntos
Córtex Auditivo/fisiologia , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Animais , Córtex Auditivo/fisiopatologia , Masculino , Ratos , Ratos Wistar
6.
Int J Oncol ; 40(3): 739-46, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22076605

RESUMO

The aim of this study was to identify a panel of methylation markers that distinguish non-small cell lung cancers (NSCLCs) from normal lung tissues. We also studied the relation of the methylation profile to clinicopathological factors in NSCLC. We collected a series of 46 NSCLC samples and their corresponding control tissues and analyzed them to determine gene methylation status using the Illumina GoldenGate Methylation bead array, which screens up to 1505 CpG sites from 803 different genes. We found that 120 CpG sites, corresponding to 88 genes were hypermethylated in tumor samples and only 17 CpG sites (16 genes) were hypomethylated when compared with controls. Clustering analysis of these 104 genes discriminates almost perfectly between tumors and normal samples. Global hypermethylation was significantly associated with a worse prognosis in stage IIIA NSCLC patients (P=0.012). Moreover, hypermethylation of the CALCA and MMP-2 genes were statistically associated to a poor clinical evolution of patients, independently of TNM tumor stage (P=0.06, RR=2.64; P=0.04, RR=2.96, respectively). However, hypermethylation of RASSF1 turned out to be a protective variable (P=0.02; RR=0.53). In conclusion, our results could be useful for establishing a gene methylation pattern for the detection and prognosis of NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Metilação de DNA , Neoplasias Pulmonares/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/patologia , Ilhas de CpG , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Prognóstico
7.
Rev. latinoam. psicol ; 43(2): 229-240, mayo 2011. tab
Artigo em Inglês | LILACS | ID: lil-637095

RESUMO

The prolonged consumption of drugs has been associated with neuropsychological and cognitive deficits. The most important deficits are associated with executive functions and memory problems, specifically with prospective memory (PM). This type of memory plays a central role in our daily life. However, there is a lack of studies on the effects of poly drug consumption on prospective memory. In this study we aim to discover to what extent the length and amount of estimated consumption of alcohol, tobacco, cannabis and tranquilizers predicts the scores of self-reported prospective memory, and the scores on two objective tasks designed for this study. Measures included a Spanish version of the UEL Recreational Drug Use Questionnaire and the Prospective Memory Questionnaire, both with objective scores on two experimental tasks. The sample was composed of 164 participants (145 females and 19 males) aged 19- 36 (M = 19.85, SD = 2.21). Stepwise regression analysis showed that years of cannabis consumption explained 13% of self-reported long term PM deficits. Years of alcohol consumption explained 18.4% of total variance of self-rated internally-cued PM deficits. Years of alcohol consumption and estimated amount of alcohol together predicted 30.2% of variance of objective event-based PM tasks. The estimated amount of tobacco and tranquilizers consumption predicted 33.7% of the time-based PM task.


El consumo prolongado de drogas se ha asociado a déficit neuropsicológicos y cognitivos. Los déficits más importantes están asociados con las funciones ejecutivas y los problemas de memoria, y en concreto con la memoria prospectiva (MP). Este tipo de memoria juega un papel central en nuestra vida diaria. Sin embargo, faltan estudios sobre los efectos del policonsumo de drogas en la MP. En este estudio pretendemos conocer en qué medida los años desde el inicio de su consumo y la cantidad de consumo estimada de alcohol, tabaco, cannabis y tranquilizantes predicen las puntuaciones autoinformadas de memoria prospectiva y las puntuaciones objetivas en dos tareas experimentales diseñadas por nosotros. Entre las medidas se incluyeron una versión en español del UEL Recreational Drug Use Questionnaire, el Prospective Memory Questionnaire, junto con las puntuaciones objetivas en dos tareas experimentales. La muestra estuvo compuesta por 164 participantes (145 mujeres y 19 varones) con edades comprendidas entre los 19 y 36 años (M: 19.85 años, DE: 2.21). Los análisis de regresión por pasos mostraron que los años de consumo de cannabis explican un 13% de los problemas autoinformados de MP a largo plazo medidos con el PMQ. En el caso de los problemas autoinformados de MP con pistas internas, son los años de consumo de alcohol los que mayor porcentaje de la varianza explican (18.4%). Respecto a las tareas objetivas de MP, los años de consumo de alcohol y la cantidad estimada de alcohol predicen el 30.2% de la varianza de la tarea prospectiva de eventos. El 33.7% de la tarea de MP de tiempo era predicha por la cantidad estimada de consumo de tranquilizantes y de tabaco.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA